Apparatus for destroying insects by means of electricity.



. F. S. SMITH. APPARATUS FOR DESTROYING INSECTS BY MEANS OF ELECTRICITY.

APPLICATION FILED JAN.7. 1911.

1,016,450, Patented Feb. 6, 1912.

UNITED sTATES PATENT ()FFICE.

FRANKLIN S. SMITH, OF PHILADELPHIA, PENNSYLVANIA.

Specification of Letters Patent.

Patented Feb. 6, 1912.

V Application filed January 7, 1911. Serial No. 601,284.

To all 'wlwm t't may concern:

Be it known that I, FRANKLIN S. SMITH, a citizen of the United States,residing in the city and county of Philadelphia, State of Pennsylvania,have invented certain new and useful Apparatus for Destroying Insects byMeans of Electricity, of which the following is a specification.

larvae and pupae, by means of electricity.

The apparatus includes means for the'production of an electric dischargeto the action of which the said insects, etc., are subjected. Theinsects, their eggs, larvae or pupae, which it is particularly desiredto destroy, are those which are destructive in various ways and whichdestroy articles of various kinds, and cause great loss of and injury toproperty.

In the apparatus illustrated herein, the discharges are caused by meansof an alternating current of commercial or slightly higher highfrequency'but it should be understood that a uni-directional current maybe' employed.

Without attempting to enumerate all of the various articles and objectswhich may" be treated for the purpose of destroying the destructiveinsects which infest and may de-' stroy them, I may mention foodproducts, such as cereals, prepared breakfast foods of the variouskinds, dried fruits, flour, figs, etc.; tobacco, either in the leafstate or after it has been converted into some form of manufacturedproduct, such as cigars and cigarettes; weari'ng apparel, such as furs,woolens, etc.; and books, papers, etc. As is well known, all of thesevarious articles may be infested and are frequently not only injured butare actually'destroyed by the in-.

sects which are peculiar thereto.

There is a species of worm, more apt to be found in the warmercountries, commonlycalled the book worm, which attacksbooks, papers,etc., and causes great injury and damage thereto. a

Employment of my invention is not limit ed to the objects and articlesdesignated above but it may be employed for the treatment of many othersnot named for the destruction of such insects as may infest them andcause their deterioration and destruct-ion.

In order that the apparatus embodying my invention, whatever its form ofconstruction, may accomplish the best results, it is necessary generallythat the objects and ar- My invention relates to apparatus or, means fordestroying insects, their eggs,

ticles treated shall be free from metallic substances, though there aresome cases which form an exception to this rule.

The objec s and articles to be treated are placed within and subjectedto the action of present any metallic substances they would act asisolated capacities and would cause a condensation of the electricalcurrent which passes through the objects or articles and thus preventcontact of the current with certain portions of the object or articlebeing treated, with the result that the material located in proximity tosuch metallic substances would be unaflected and unacted upon by thedischarge current through the articles or object being treated.

Cereals and breakfast foods generally may be treated in bulk or in theusual card board boxes in which they are sold but when treat ed in suchboxes care must be taken to pre-' vent the presence of metal upon. thesaid boxes. Also cigars and cigarettes may be treated in bulk or in theboxes in which they are sold or marketed. The difliculty, however, intreating cigars and cigarettes in boxes as suggested is that such boxesusually are provided with decoration which includes a greater or lessamount of metallic substance which would interfere with the successfuloperation of my invention and discovery inthe treatment of cigars inboxes; hence, cigars and cigarettes preferably should be treated in bulkand before being placed in the boxes in which they are marketed. In thetreatment of clothing, care must be exercised to prevent the presence ofmetallic buttons because if such buttons are present and cause aconcentration of the current at thepoints where they are located so asto prevent the action of the current upon the electrical discharges andif there should be they act as conductors, as already indicated,

portions of the material of the garment which are in proximity to andsurround the said buttons.

In the employment of apparatus embodying my invention in the treatmentof articles, such-as are above suggested, care must be exercised toprevent their oxidation and carbonization by the use of discharge sparkswhich are of too great capacity. The capacity of the sparks may becontrolled in various ways and by experience it has been found thatsparks may be produced'and employed in the carrying out and practicingof my invention which are of sufiicient capacity to destroy the insects,their eggs, larvae or pupze, which may be upon the articles treated butwhich will not cause injury to the articles themselves.

In the large number of experiments 'which I have heretofore carried outin the development of my invention, I have discovered that whencarefully and intelligently employed and operated, my invention willdestroy all of the insects in whatever stage of their development,whether as eggs, larvae, 'pupie or adults, which may infest or bepresent in or upon the articles or objects treated.

In the accompanying drawings I have illustrated a convenient embodimentof my invention but it will be understood and will be apparent from thedescription of the same which follows, that my invention may be embodiedin other forms of construction.

In the drawings :Figure 1 is a top plan view of an apparatus embodyingmy invention; Fig. 2 is a sectional side elevation of the same; and Fig.3 is an enlarged View on the line 3-3 of Fig. 1 showing more clearly adetail of construction.

Referring to the drawings :the numeral 1 designatesa source ofalternating electric current, 2 a switch, and 3 a variable or adjustableresistance which is connected in series with the primary coils of anumber of step-up transformers 5 which are connected in multiple withthe source 1 of current.

The opposite ends of the secondary coils of the said transformers 5 areconnected with the oppositely disposed electrodes 6 and 7. Theseelectrodes are arranged in two rows, as is indicated in Fig. 1 of thedrawings. The electrodes in the two upper rows are arranged in staggeredrelation with respect to each other, as is clearly shown in Fig. 1,while those in the two lower rows are arranged in staggered relationwith respect to each other in the same manner. The number oftransformers, electrodes, and arrangement of the latter may be varied asdesired. Preferably,'though in some cases it may be found to beunnecessary, the electrodes should respectively 'terminate in a singlepoint in order that all portions of the object or article being treated,whether in boxes or otherwise, may be subjected to the action of thedischarge. It has been found that if electrodes of considerable lengthand respectively provided with a plurality of points are employed andarticles are treated in boxes, it happens that the discharge takes placebetween points of opposing electrodes .which are nearest to alinementwith a side of the said boxes along the said side so that the materialin the boxes may not be acted upon.' In such cases, the insects or theireggs, larvae or pupae, which may be present in the articles and which itis desired to destroy, remain unharmed:

The electrodes 6 and 7 are supported in depressions or seats 10 and 11formed in plates 12 and 13.0f non-conducting or insulating material,such as glass or porcelain. It will be understood that when the switch 2is closed an electric discharge takes place between electrodes 6 and 7,such discharge consisting of well defined sparks and also of what isknown as efiiuve, both of which are visibly apparent. The plates 12 and13 are supported in any suitable manner, as for instance upon posts orstandards 14 and 15. It will be observed that the electrodes 6 priojecta short distance below the lower 51 e ends of the electrodes 7 arelocated a short distance below the upper side of the plate 11.

20 designates a conveyer of suitable insulating or non-conductingmaterial supof the surface of the plate 10 while the ported uponrevoluble wheels 21 driven from any suitable source of power (notshown), by means of which articles being treated are conveyed into andacross the space between the electrodes 6 and 7. The electrodes in therespective rows should be arranged close together and those in therespective plates upon which they are supported should be in staggeredrelation with respect to each other, as indicated in Fig. 1.

It is desirable that the electrodes should be arranged closely togetherand in staggered relation, as illustrated, in order that as an articleis passed between the electrodes upon the conveyer 20 or by any othermeans supported intermediate or moved between and past the electrodes,all parts thereof are subjected to the action of the discharge; in otherwords, there should be no wide gaps in the line or curtain of dischargethrough which an article or portions of an article may be passed withoutbeing acted upon thereby.

As already indicated, the apparatus or machine illustrated hereinproduces low frequency electrical oscillations of commercial or slightlyhigher frequency. The said machine produces an alternating electriccurrent but it will be understood by those skilled in the art relatingto electrical machines that the current may be changed by known meansfrom an alternating to a unidirectional current.

In order to operate the apparatus illus-, trated, the switch 2 should beclosed and the! variable or adjustable resistance 3 adjusted! asdesired. The capacity of the discharge spark may be controlled to someextent by adjusting the resistance 3 but it is principally dependentupon the transformers 5. In order to secure the best results, thedistance between the electrodes 6 and the surface of the top portion ofthe conveyer 20 or other supporting means should be only slightlygreater than the height or thickness of the objects or articles whichare being treated in the apparatus. As the arti cles being treated areplaced in position in the space between the electrodes they are actedupon by the electrical discharge which takes place between the saidelectrodes, the passage of which through the objects effects or causesthe destruction and killing of the insects, their eggs, larvae or pupae,which may be present. It is my understanding and belief that the sparksare the portion of the discharge which is effective in destroying theinsects, their eggs, larvae or pudae, and that the efiiuve does notdestroythem.

In the treatment of tobacco in and by the apparatus herein described,whether it be in the form of cigars or in bundles or bales prior tobeing converted into a manufactured product, the leaves thereof shouldbe placed in the machine or apparatus for treatment so that they extendsubstantially in parallel relation with the direction of the lines ofdischarge of the electric sparks between the opposing electrodes. If thetobacco is so placed that the lines of discharge take place transverselyof the leaves, the said discharges are apt. to pass directlytherethrough without spreading over their surfaces and in consequenceare not likely to destroy all of the insects. It is also the case thatif the discharge takes place transversely of the leaves of the latter itis likely thatthe latter would be carbonized. The voltage should also beadjusted or varied so as'to correspond with the capacity or conductivityof the article being treated. For instance, the voltage necessary totreat successfully a column of tobacco of a certain definite size andheight should be less than that employed in the treatment of a column ofthe same size and height of some other substance of less conductivity,for instance, a cereal.

In the construction as illustrated, the electrodes are'so arranged thatthe discharge produced forms substantially a curtain so, that if anarticle or object is pass'ed'between the electrodes, every part thereofis subjected to the action of the discharge and all of the insects,their eggs, larvae or pupae, are

destroyed. It is to be understood, however, that my invention is notlimited tothe specific arrangement of electrodes illustrated. I havediscovered. that the said insects,

etc., are killed immediately by the action ofthe said sparks, and I havediscovered also that the said sparks seek out the said insects, eggs,larvae or pupae, wherever they may be in the package and destroy them.

The broad subject matter of'invention disclosed herein and not claimedis claimed in my co-pending application filed January.

7th, 1911, Serial No. 601,283.

The term electrode or electrodes employed herein is not one oflimitation but of description and includes any terminal, as for instancethe ends of the secondary coil, from which electrical discharges takeplace.

Having thus described my invention, I claim 2-- 1. In an apparatus ofthe characterdescribed, the combination of a source of alternatingelectric current, transformers the primany coils of which are connectedthereto,"

electrodes or terminals connected to the opposite ends of the secondarycoils of said .transformers, the said electrodes or terminals beingarranged in electrically independent pairs and in oppositely disposedgroups and the electrodes or terminals in each group being situated inrows in staggered relation with respect to each other, and meansconsisting of non-conductive material for supporting articles or objectsbetween the said electrodes or terminals whereby the electricaldischarges between the said electrodes may pass through said articlesand objects and destroy any insects, their eggs, larvae or pupae whichmay be therein'or thereon.

2. In apparatus of the character described, the combination of a sourceof elecpositely arranged electrodes connected to said transformers, thesaid electrodes being arranged in electrically independent pairs andeach pair having connection with a different transformer, and means forsupporting articles between said electrodes.

4. In apparatus of the character described, the combination of a sourceof alternating electric current, a plurality of transformers of smallcapacity, a plurality of electrodes in oppositely arranged groups havingconnection in electrically independas my invention, I have hereuntosigned my entdpairs with said gransformers, this1 el lecname this 4thday of January, A. D. 1911.. tro es in eao group eing in staggere re a-T T tion with respect to each other, and means FRAI RLII SMITH 5 forsupporting articles between said groups In the presence of ofelectrodes. GEO. H. WEIDNER,

In testimony that I claim the foregoing CARRIE E. KLEINFELDER.

